地球同步轨道空间目标地基逆合成孔径激光雷达系统分析

System Analysis of Ground-based Inverse Synthetic Aperture Lidar for Geosynchronous Orbit Object Imaging

对用于地球同步轨道空间目标进行成像观测的地基逆合成孔径激光雷达系统进行了分析.讨论了地球同步轨道空间目标运动特性和观测几何模型,分析了地基逆合成孔径激光雷达系统指标,波形选择为无周期相位编码信号,提出了基于发射和本振参考通道的信号相干性保持方法.根据目标存在振动和三维自转的特点,采用正交基线干涉处理的方法进行运动相位误差估计与补偿.引入自适应光学系统实现大气时变相位误差校正,同时明确了基于正交基线干涉处理的逆合成孔径激光雷达与自适应光学在大气校正方面具有互补性.设计了初步系统方案,仿真验证了目标振动和三维自转对逆合成孔径激光雷达成像有明显的影响.

In this paper,the ground-based inverse synthetic aperture lidar for geosynchronous orbit objects imaging is analyzed. The motion characteristics and observation geometric of geosynchronous orbit objects are discussed and the system parameters of inverse synthetic aperture lidar are analyzed. The waveform is chosen to be acyclic phase-coded signal. A signal coherence preserving method based on both transmitting and local oscillator reference channels is proposed. Since the object has both vibration and three-dimensional rotation,the motion phase error estimation and compensation are implemented based on orthogonal baselines interferometry processing. The adaptive optics system is introduced to complete the time-varying phase error correction,which results from atmospheric turbulence. Moreover,it ＇s clarified that the inverse synthetic aperture lidar based on orthogonal baselines interferometry processing and the adaptive optics are complementary in the atmospheric correction. A preliminary system scheme is designed and simulation results show that the target vibration and three-dimensional rotation have a significant influence on inverse synthetic aperture lidarimaging.